Piezoelectricity of phospholipids: a possible mechanism for mechanoreception and magnetoreception in biology

Abstract

We show that phospholipids, which are the main constituents of cell membranes, are piezoelectric. This was done by periodically shearing and compressing films of hydrated l‐α‐phosphatidylcholine, inducing a tilt of the molecules with respect to the bilayer’s normal, which produced an electric current perpendicular to the tilt plane, corresponding to a polarisation of about 300 nC cm⁻² at 5° of tilt. We also measured electric currents induced by an alternating magnetic field of less than 100 G in hydrated phospholipids doped with 0.5 wt% of ferrofluid of magnetite (Fe₃O₄) nanoparticles. A discussion of possible implications of these effects on biophysical processes is also provided.

Keywords:

• lipids
• piezoelectricity
• magnetoreception
• mechanoreception

Acknowledgements

The work was partially supported by NSF DMS 0456221. We thank Professor Philip Westerman for helpful discussions, and Dr G. Liao, Ms T. Heatdrech and Mr C. Braganza for their involvement in early stages of the experiments.